Doing stuff like this in the 8-bit era was never particularly hard. The difficulty was doing this and then anything else, because you basically need the entire CPU just for audio synthesis. For games, there was a very real trade-off between calculating video, game state, and sound, and sound often took the back seat.
It's also why everything looked and sounded better on 8-bit computers that had hardware support for graphic sprites or sound generation, even if they had a less powerful CPU. And it's the untold story behind why 16-bit graphics looked so much better: it wasn't about the CPU as much as it was about having a dedicated video card / chipset with its own memory, a sound card that handled polyphonic sound and MIDI synthesis, etc.
Does the Speccy have enough outputs on the edge connector to make a simple DAC like the parallel port ones we used to make with a bunch of resistors for the PC?
I have a memory of a Spectrum game playing some sort of synthesised speech through the speaker that seemed incredibly ahead of its time. I believe the game was called iBall. And the sample said something like “Fight iBall!” Have I misremembered that? Was this a fever dream?
Although tbf apparently that's done via the AY sound chip of the 128k, which is a lot easier than through the on/off beeper of the 48k since the AY can do digitized audio via CPU-driven volume modulation.
The 128k version of Nodes of Yesod had some speech, albeit I think it was just the name of the game. My older brother told me a kid in his class got paid big bucks - like, I dunno, £50 or something? - for coding it. Almost certainly bollocks.
For some reason "5", even if constructed as phonemes came out as "frame" - I always wondered why. I've never seen it mentioned in the various short pieces about it online including its contemporary reviews. I wonder now if it was a bug in the particular rom I had and it was fixed early enough to not get much visibility.
There was a music editor I remember getting on a late Your Sinclair edition cover tape which displayed proper music staves and gave you 4-note chord output. Blew my mind a bit at the time.
Due to all the constraints the ZX Spectrum is a fantastic system for recreational programming; too bad I missed the latest Spectrum Next batch last year.
The computed jump into a NOP sled is a nice trick for getting a fine-grained delay without spending registers on a counter. I'm curious how much contended memory got in the way: on the 48K, code or sample data sitting in the lower 16K gets stalled by the ULA during screen fetch, which seems like it would wreck cycle-exact pulse widths unless everything lives above 0x8000. Did you end up having to place things carefully for that, and did the 128K/+2/+3 contention differences show up in the hardware tests? It's also interesting that the first attempts mostly produced the 8kHz carrier, since that's squarely in the audible range where the PC's 16kHz-ish carrier was easier to ignore.
It's also why everything looked and sounded better on 8-bit computers that had hardware support for graphic sprites or sound generation, even if they had a less powerful CPU. And it's the untold story behind why 16-bit graphics looked so much better: it wasn't about the CPU as much as it was about having a dedicated video card / chipset with its own memory, a sound card that handled polyphonic sound and MIDI synthesis, etc.
https://www.theregister.com/offbeat/2026/09/13/the-improbabl...
I got some valuable links to tunes from a previous HN thread:
https://news.ycombinator.com/item?id=49611230
It was just 3 weeks ago...
e.g. the homemade versions of this:
https://en.wikipedia.org/wiki/Covox_Speech_Thing
https://www.youtube.com/watch?v=Dy8kZcGz98U
There were a few games (in later years) with speach/audio. But Robocop was one that stands in my memory for the good music.
https://youtu.be/yjrbcLm78I8?si=GMIqDdL31hq4ik72&t=87
Although tbf apparently that's done via the AY sound chip of the 128k, which is a lot easier than through the on/off beeper of the 48k since the AY can do digitized audio via CPU-driven volume modulation.
https://spectrumgamesuk.com/index.php?game=Meteor-Storm
I think it said "Meteor Alert!" or something similar, though the quality was terrible.
For high quality speech, you could get the Currah μSpeech! https://en.wikipedia.org/wiki/Currah#Currah_%CE%BCSpeech_for...
I swear there was one symbol it pronounced "flea bleep".
(And there was a "Get ready!" which I didn't remember)
https://www.youtube.com/watch?v=hRW9vW3_M3o&t=8
https://zxart.ee/prod/101558
https://news.ycombinator.com/item?id=49895486
There's also a phone with YM2149
https://www.youtube.com/watch?v=u-D24A_N4d4
https://www.youtube.com/watch?v=PTGkf21UpJ8
How it works: https://livet.se/mahoney/c64-files/Cubase64_White_Paper_by_P...